TROJ_UTOTI.JH
Worm:AutoIt/Autorun.N (Microsoft); W32/Autorun.worm.bcb (McAfee); W32.SillyFDC (Symantec); Trojan-Dropper.Win32.Autoit.kh (Kaspersky); Worm.Win32.Abfewsm.a (v) (Sunbelt); Trojan horse Generic17.AFBQ (AVG)
Windows 2000, Windows XP, Windows Server 2003
Threat Type: Trojan
Destructiveness: No
Encrypted:
In the wild: Yes
OVERVIEW
This Trojan arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.
It disables Task Manager, Registry Editor, and Folder Options.
TECHNICAL DETAILS
590,848 bytes
EXE
Yes
15 Oct 2013
Arrival Details
This Trojan arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.
Installation
This Trojan drops the following copies of itself into the affected system:
- %System Root%\KHATRA.exe
- %System%\KHATRA.exe
- %Windows%\Xplorer.exe
- %System%\gHost.exe
- %Windows%\KHATARNAKH.exe
(Note: %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.. %System% is the Windows system folder, which is usually C:\Windows\System32.. %Windows% is the Windows folder, which is usually C:\Windows.)
Autostart Technique
This Trojan adds the following registry entries to enable its automatic execution at every system startup:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Winlogon
Taskman = "%System%\KHATRA.exe"
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
Xplorer = "%Windows%\Xplorer.exe /Windows"
Other System Modifications
This Trojan adds the following registry keys:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\policies\
Explorer\Run
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
System
HKEY_CURRENT_USER\Software\Nico Mak Computing\
WinZip\caution
It adds the following registry entries:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\policies\
Explorer\Run
G_Host = "%System%\gHost.exe /Reproduce"
HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Main
Window Title = "Internet Exploiter"
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Schedule
AtTaskMaxHours = "0"
HKEY_CURRENT_USER\Software\Nico Mak Computing\
WinZip\caution
NoUnsafeTypeCautionForSCR = "1"
HKEY_CURRENT_USER\Software\Nico Mak Computing\
WinZip\caution
NoUnsafeTypeCautionForEXE = "1"
It modifies the following registry entries:
HKEY_CURRENT_USER\Software\Microsoft\
Windows NT\CurrentVersion\Windows
Load = "%System%\KHATRA.exe"
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
Hidden = "0"
(Note: The default value data of the said registry entry is 2.)
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced\Folder\Hidden\
SHOWALL
CheckedValue = "0"
(Note: The default value data of the said registry entry is 1.)
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
Explorer
NoDriveTypeAutoRun = "ff"
(Note: The default value data of the said registry entry is 91.)
It creates the following registry entry(ies) to disable Task Manager, Registry Tools and Folder Options:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
System
DisableRegistryTools = "1"
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
Explorer
NoControlPanel = "1"
Dropping Routine
This Trojan drops the following files:
- %Common Startup%\(Empty).LNK
(Note: %Common Startup% is the system's shared Startup folder, which is usually C:\Documents and Settings\All Users\Start Menu\Programs\Startup on Windows 2000, XP, and Server 2003.)
This report is generated via an automated analysis system.
SOLUTION
9.300
Step 1
Before doing any scans, Windows XP, Windows Vista, and Windows 7 users must disable System Restore to allow full scanning of their computers.
Step 2
Identify and delete files detected as TROJ_UTOTI.JH using either the Startup Disk or Recovery Console
Step 3
Enable Registry Editor, Task Manager, and Folder options
Step 4
Delete this registry key
Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this step only if you know how or you can ask assistance from your system administrator. Else, check this Microsoft article first before modifying your computer's registry.
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\policies\Explorer
- Run
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies
- System
- In HKEY_CURRENT_USER\Software\Nico Mak Computing\WinZip
- caution
Step 5
Delete this registry value
Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this step only if you know how or you can ask assistance from your system administrator. Else, check this Microsoft article first before modifying your computer's registry.
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon
- Taskman = "%System%\KHATRA.exe"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
- Xplorer = "%Windows%\Xplorer.exe /Windows"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\policies\Explorer\Run
- G_Host = "%System%\gHost.exe /Reproduce"
- In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main
- Window Title = "Internet Exploiter"
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Schedule
- AtTaskMaxHours = "0"
- In HKEY_CURRENT_USER\Software\Nico Mak Computing\WinZip\caution
- NoUnsafeTypeCautionForSCR = "1"
- In HKEY_CURRENT_USER\Software\Nico Mak Computing\WinZip\caution
- NoUnsafeTypeCautionForEXE = "1"
Step 6
Restore these modified registry values
Important:Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this only if you know how to or you can seek your system administrator's help. You may also check out this Microsoft article first before modifying your computer's registry.
- In HKEY_CURRENT_USER\Software\Microsoft\Windows NT\CurrentVersion\Windows
- Load = "%System%\KHATRA.exe"
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
- From: Hidden = "0"
To: Hidden = ""2""
- From: Hidden = "0"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Advanced\Folder\Hidden\SHOWALL
- From: CheckedValue = "0"
To: CheckedValue = ""1""
- From: CheckedValue = "0"
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer
- From: NoDriveTypeAutoRun = "ff"
To: NoDriveTypeAutoRun = ""91""
- From: NoDriveTypeAutoRun = "ff"
Step 7
Search and delete this file
- %Common Startup%\(Empty).LNK
Step 8
Scan your computer with your Trend Micro product to delete files detected as TROJ_UTOTI.JH. If the detected files have already been cleaned, deleted, or quarantined by your Trend Micro product, no further step is required. You may opt to simply delete the quarantined files. Please check this Knowledge Base page for more information.
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